When someone begins to dislike a band, movie, tv show or any other element of popular culture solely based on the fact that it has become popular.

This is something that hipsters do on a regular bases in order to remain relevant. It is the ultimate betrayal because at one point you consider this band or movie to be amazing and now that it has gain recognition instead of being happy you reject it and call it "mainstream".

Hispter: I used to like Arcade Fire but then they became so main stream. I can't even listen to their music any more.

Non-Hipster: Arcade Fire is exactly the same as they used to be, you just doing the Hipster Betrayal.